Mike,

You may have already seen this, but here's an interesting  discussion 
from W8JI on the relay subject:

http://www.w8ji.com/relay_cleaning_and_life.htm

73, Steve KW3A

On 3/26/2015 8:06 AM, Michael Ryan wrote:
> Hi all: =20
>
> As modern rigs have problems keying an older amplifier, like a Heathkit =
> SB-220, Drake L-4 etc,=20
> with out the employment of a buffer box, can the opposite apply?=20
> Can a vintage transceiver, which most likely has much higher voltage to =
> key the older amps, put to much voltage into a modern amp's relay?=20
> Can damage occur to the transceiver if to much voltage is being used?=20
> I have a very sticky relay in my AL-811H and when it sticks, the RX =
> drops way down on the 102.=20
> The only way to restore the RX is to: 1, tap the amp on the cabinet =
> where the relay board is,=20
> 2, switch the amp into standby and back into operate or tap the PTT on =
> my desk mic or foot switch.=20
> I'm also concerned about over driving that may have caused some damage.=20=
>
> My rig's SSB output uses the mic gain control to very the output.=20
> So even though I use CW to tune up things, switching to SSB probably =
> changes everything as the rig uses the mic gain to control the output on =
> SSB.=20
> My mic gain's position is about 9 o'clock and either barefoot or using =
> the amp, I don't change it.=20
> So its possible I'm over driving the amp on times. What kind of damage =
> can occur?=20
> On another note with the 102 it self:=20
> I'm still blowing a fuse every 3 months or so, about a total of 24 hours =
> of actual operating and I'm told that its my tubes.=20
> However, I don't see how as I'm still getting full output from the =
> tubes.=20
> If the tubes are indeed bad or on there way out, shouldn't I have =
> reduced output, getting lower and lower?=20
> Or when a tube goes, it goes at once from full output to half power etc?=20=
>
>
> 73:=20
> Mike DE VO1AX =20
>
>
>